Respiratory System: Anatomy and Function
Air Conducting Part
The air conducting part starts in the nose and mouth and continues with the nasal cavity, pharynx, larynx, trachea, and bronchi. Function: It carries air to the lungs and has other respiratory functions.
Vocal Tract
The vocal tract constitutes the lungs and pleura. Function: Blood gas exchange.
True or False
- False – Located in the chest.
- False – The lungs are two spongy, elastic, and conical sacs located in the thoracic cavity.
- False – The right lung has 3 lobes, and the left has 2 lobes.
- False – The mediastinum is the space containing the heart and other thoracic organs.
- False – The lungs have a hole called the hilum.
- True
- False – The lungs rest on the diaphragm.
Larynx Structure
The larynx consists of articulated cartilage, joined by ligaments and muscles. Functions: It joins the air duct and acts as a phono conduit. It joins the hyoid bone above by ligaments and the trachea below by a membrane.
Laryngeal Cartilages
- Thyroid: Located below the hyoid bone, it is wide and open at the back, presenting 4 horns (2 superior attached to the hyoid and 2 inferior hinged to the cricoid).
- Cricoid: Similar to a seal ring oriented backward.
- Arytenoid: Located on the back of the cricoid and superior, one on each side.
- Epiglottis: Oval thyroid lamina behind, above the upper hole of the larynx.
Main Function of the Epiglottis
The epiglottis closes the input to the larynx during swallowing to avoid introducing solids or fluids into the air tubes.
What is the Glottis?
The glottis is the laryngeal cleft on the canal with a very variable amplitude, limited by 4 folds, 2 on each side (vocal cords).
Why Can the Name of Pulmonary Blood Vessels Be Confusing?
We call pulmonary blood vessels “arteries” or “veins” as if they carry or bring blood from the heart to the lungs when actually they contain venous or arterial blood, respectively.
How is the Heart Joined to the Lungs?
The heart is joined to the lungs by the pulmonary pedicle, which has blood vessels, lymph vessels, nerves, and bronchi.
Where Do Pulmonary Veins Originate?
Pulmonary veins originate from the capillaries of the networks of the lobules, the last branches of the bronchi. These venules converge toward the pulmonary hilum, joining vessels to form increasingly thick and large veins, forming 2 that leave each lung.
Anatomical Constitution of the Lung
Lung alveoli, infundibulum (set of alveoli), acinus (set of infundibula, approximately 6), branching intralobular bronchioles, lobule, lung.
Where Does Blood Gas Exchange Take Place in the Lung?
Blood gas exchange takes place in the walls of the pulmonary alveoli. They are very thin membranes separating air from blood.
Where Does the Respiratory and Circulatory System Join?
The respiratory and circulatory systems join between the alveolar wall and the capillary network surrounding the alveoli.
Pulmonary Ventilation
Pulmonary ventilation involves movements performed by inspiration and expiration, involving the rib cage, diaphragm, intercostal muscles, and pleura.
- Inspiration: The diaphragm stretches as it brings down the lungs, creating more space to expand and thus vacuum air.
- Expiration: The diaphragm relaxes, pushing back up to the lungs against the chest cavity, reducing their space and expelling air.
True or False
- False – Inspiration is passive and is due to diaphragm motion.
- False – The lung volume increases during inspiration.
- False – Expiration is passive.
- True
- True – Specifically in the lobules of the lung periphery.